The invention relates to a medical instrument with a shank, a housing and an openable and closable two part tool which is provided at the distal instrument end and which for closing and opening can be actuated by the axial shifting of an actuating element running through the housing and the shank, and with an elastic buffer as an overload protection which in the case of overloading by way of elastic deformation buffers an axial force transmitted from the actuating element onto the shank.
With such a medical instrument designed as a microsurgical forceps (DE 36 01 166 A1) the flow of force is guided from the grip part to the associated jaw part via a two-part element. This element is held together by the buffer exerting a predetermined elastic pretension in the position in which it transmits the force exerted onto the grip parts onto the jaw parts. If this force exceeds the pretension of the buffer then the element is separated against the effect of the pretensioning. Thus the force transmitted onto the jaw parts may not exceed the value predetermined by the pretension of the buffer and a breakage of the jaw parts is ruled out.
With this instrument the buffer is designed as a metallic helical spring which lies within the instrument housing. On account of this constructional type there results considerable constructional size, a complicated assembly and high manufacturing costs. Furthermore the spring force of the helical spring serving as a buffer may not be simply influenced by way of a directed selection of material.